You're probably right that she isn't a pornstar. Though I wouldn't call her an extra in the scene either. If I was to guess, she is most likely a friend of Whitney Wright. Sometimes it helps to have a friend there to help to relax Whitney right before the scene starts with Nathan Bronson.
Aletta Ocean did that. Had a behind the scenes video that she made. Aletta had a girlfriend talk and walk in a park with a videographer present. Aletta and her friend got blue cotton candy which they had fun eating. And Aletta and her friend then rented a two wheeled bicycle contraption that had two seats which they pedaled. The videographer sat in one of the seats and filmed them.